public class googleChartCon {
private String chartData;

public String getChartData()
{
 return chartData;
}

public googleChartCon()
{
 //obtain a list of picklist values
 Schema.DescribeFieldResult F = Account.Type.getDescribe();
 List<Schema.PicklistEntry> P = F.getPicklistValues();
 //where chart data should be stored.
 List<ChartDataItem> items = new List<ChartDataItem>();

 //iterate through each picklist value and get number of accounts
 // I wish we could do GROUP BY in SOQL!
 for(Schema.PicklistEntry pValue : P)
 {
    integer Count = [select count() from Account where Type = :pValue.getValue() limit 10000];
    if (Count > 0)
      items.add(new ChartDataItem(pValue.getValue()+ '-['+ Count.format() + ']' , Count.format()));
 }

 //Prepare the chart URL
 String chartPath = 'http://chart.apis.google.com/chart?chs=600x200&cht=p3';
 chartData = chartPath +  getChartData(items);
}

private String getChartData(List<ChartDataItem> items)
{
 String chd = ''; //23,34,56
 String chl = ''; //Hello|World

 for(ChartDataItem citem : items)
 {
    chd += citem.ItemValue + ',';
    chl += citem.Label + '|';
 }
 //remove the last comma or pipe
 chd = chd.substring(0, chd.length() -1);
 chl = chl.substring(0, chl.length() -1);

 String result = '&chd=t:' + chd + '&chl=' + chl;
 return result;
}

public class ChartDataItem
{
     public String ItemValue{get;set;}
    
     public String Label{get; set;}
     
     public ChartDataItem(String Label, String Value)
         {
            this.Label = Label;
            this.ItemValue = Value;
         }
    

}

}